I wrote a post about this outstanding resource, which only recently came to my attention—over a century after it was published!
Hugo Hurter (1832–1914), ed., Nomenclator literarius recentioris theologiae catholicae theologos exhibens qui inde a Concilio tridentino floruerunt aetate, natione, disciplinis distinctos, 4 vols. (Oeniponte [Innsbruck]: Libraria academica Wagneriana, 1892–99).
- Vol. 1 (1892): Theologiae Catholicae seculum primum post celebratum Concilium Tridentinum, ab anno 1564–1663 [Hathi Trust]
- Vol. 2 (1893): Theologiae Catholicae seculum secundum post celebratum Concilium Tridentinum, ab anno 1664–1763 [Hathi Trust]
- Vol. 3 (1895): Theologiae Catholicae seculum tertium post celebratum Concilium Tridentinum, ab anno 1764–1894 [Hathi Trust]
- Vol. 4 (1899): Theologia Catholica tempore Medii Aevi, ab anno 1109–1563 [Hathi Trust] [index of names for all 4 volumes]
This work provides exhaustive documentation for every Catholic theological writer who was working between 1109 and 1894.
(There was a further third edition, with a different arrangement, that took the contents down to the year 1910, and some of these volumes are accessible online at the Internet Archive. But unlike the second edition, the third seems not to have had a union index of names across all the volumes, which makes it rather less useful for my purposes.)
As I said in that post, I’ve found it especially useful for figuring out abbreviated references in older scholarly works, which often give just the first few letters of an author’s name, on the assumption that the reader will know who is meant.
In such cases, I look in the complete index to all four volumes (at the end of volume 4) and cross-reference the volume and page numbers in the index with the analytical table of contents in each volume, which gives an idea of the disciplinary focus of the author referred to.
To make that easier for myself and others, I’ve created a pdf file of the union index and another containing the tables of contents from all four volumes: